/*
* Copyright (c) 1998, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package sun.awt.geom;
final class ChainEnd {
CurveLink head;
CurveLink tail;
ChainEnd partner;
int etag;
public ChainEnd(CurveLink first, ChainEnd partner) {
this.head = first;
this.tail = first;
this.partner = partner;
this.etag = first.getEdgeTag();
}
public CurveLink getChain() {
return head;
}
public void setOtherEnd(ChainEnd partner) {
this.partner = partner;
}
public ChainEnd getPartner() {
return partner;
}
/*
* Returns head of a complete chain to be added to subcurves
* or null if the links did not complete such a chain.
*/
public CurveLink linkTo(ChainEnd that) {
if (etag == AreaOp.ETAG_IGNORE ||
that.etag == AreaOp.ETAG_IGNORE)
{
throw new InternalError("ChainEnd linked more than once!");
}
if (etag == that.etag) {
throw new InternalError("Linking chains of the same type!");
}
ChainEnd enter, exit;
// assert(partner.etag != that.partner.etag);
if (etag == AreaOp.ETAG_ENTER) {
enter = this;
exit = that;
} else {
enter = that;
exit = this;
}
// Now make sure these ChainEnds are not linked to any others...
etag = AreaOp.ETAG_IGNORE;
that.etag = AreaOp.ETAG_IGNORE;
// Now link everything up...
enter.tail.setNext(exit.head);
enter.tail = exit.tail;
if (partner == that) {
// Curve has closed on itself...
return enter.head;
}
// Link this chain into one end of the chain formed by the partners
ChainEnd otherenter = exit.partner;
ChainEnd otherexit = enter.partner;
otherenter.partner = otherexit;
otherexit.partner = otherenter;
if (enter.head.getYTop() < otherenter.head.getYTop()) {
enter.tail.setNext(otherenter.head);
otherenter.head = enter.head;
} else {
otherexit.tail.setNext(enter.head);
otherexit.tail = enter.tail;
}
return null;
}
public void addLink(CurveLink newlink) {
if (etag == AreaOp.ETAG_ENTER) {
tail.setNext(newlink);
tail = newlink;
} else {
newlink.setNext(head);
head = newlink;
}
}
public double getX() {
if (etag == AreaOp.ETAG_ENTER) {
return tail.getXBot();
} else {
return head.getXBot();
}
}
}